While nonsurgical treatment for back pain is the treatment of choice, spine surgery becomes an option when neck and low back pain is disabling and not responding to nonoperative treatment alternatives. Further, in some cases such as certain fractures, infections, tumors, and severe neurologic deficits, surgery is the first treatment choice. As mentioned in earlier sections, the information we have with respect to surgical procedures is limited to that obtained from hospitals using the Nationwide Inpatient Sample and the National Hospital Discharge Survey. Because of the larger sample size, most data in this analysis uses the NIS. Unfortunately, the information is procedure-related and only indirectly patient-related. On average, two of the eight most common procedures were performed on most patients because the sum of the percentage of patients receiving a procedure is nearly twice that of procedures. (Reference Table 2.12 PDF [1] CSV [2])
In 2007, just under 1.187 million procedures for the eight most common spine procedures were performed on 662,400 patients. In 2011, the number of patients had increased to 741,700, but total procedures for the same eight common procedures jumped even more to 1.391 million. This is an increase in the number of procedures by 17%, but only a 12% increase in the number of patients.
In 2007, there were 332,500 diskectomies performed compared to 369,900 in 2011. Because of the increase in spinal fusion and other procedures, as subsequently discussed, hospital diskectomies constitute 28% and 25% of all spine procedures in the two years, respectively. Although an absolute larger number of procedures in 2011, diskectomies represent a decreasing share of all procedures in 2011. To what degree this reflects a transfer of procedures to surgicenters is unknown because there is currently no national database. Spinal fusion procedures were listed as the main hospital procedure, being performed on 380,000 patients in 2007 and 457,500 patients in 2011. The majority of insertions of spinal devices, the third most common procedure group, likely occurred in patients with spinal fusions. If we assume that all patients in whom spinal devices were inserted also were fused, only 142,000 patients who were fused did not get a spinal device (18%). Spinal decompression, which may or may not be performed in conjunction with a spinal fusion or in conjunction with a diskectomy, accounted for 14% of all procedures in 2007 and 12.5% in 2011, an decrease of only 7% in the number of procedures. The number of spinal decompression procedures performed, along with other procedures for which inpatient hospitalization is not always required, may not be reflected accurately because an increasing number of these patients are operated on in outpatient surgicenters and facilities,.
The rate of spinal fusion procedures has risen rapidly over the past several decades. Spinal fusion is performed either alone or in conjunction with decompression and/or reduction of a spinal deformity. Fusions are performed on all regions of the spine. Between the years 1998 and 2011, the number of spinal fusion procedures has more than doubled, from 204,000 in 1998 to 457,000 in 2011. This is a 14-year increase of 113%. Apart from the period from 2002 to 2004, the increase on a biyearly basis is in the double digits. Relating the number of patients operated on to the estimated population age 18 years and older, the rate has gone from 110 per 100,000 persons in 1998 to 199 per 100,000 in 2011. During the same time period, refusion rates increased by 171%, from 6 to 14 persons per 100,000. Between 1998 and 2011, the average age of patients operated on with a fusion procedure has increased from 49 years to just under 56 years. (Reference Table 2.13 PDF [3] CSV [4])
Although the mean length of stay for spinal fusion has decreased from 4.7 days in 1998 to 3.8 in 2011, the hospital charges for these patients have increased significantly. The mean hospitalization charge in 1998 was $26,000 ($36,000 in 2011 dollars); while in 2011 the charge was $102,000. An increased use of instrumentation and biologicals (mainly bone substitutions) contribute to the higher cost. The total increase in hospitalization charges rose from $5.4 billion ($7.4 billion in 2011 dollars) to $46.4 billion over this 14-year period, an increase of more than 750%. Spinal refusions are even more expensive, with an average charge of $123,000 in 2011. However, because spinal refusions are a small proportion of all fusion procedures, they account for only 7.5% of total 2011 charges. This, of course, does not mean that cost or reimbursement was even close to these dollar numbers. These charges are based on what hospitals set as their charges, and do not reflect the contractual agreements they have with the payor community.
Likely explanations for the increase in spinal fusions are advances in technology, including the development of new diagnostic techniques and new implant devices that allow for better surgical management. In addition, there has been increased training in spinal surgery and the population has aged, bringing with it the inherent medical problems that aging incurs. Further, quality of life expectations have increased, making patients less accepting of an ongoing back problem and more likely to look for a surgical solution.
Lumbar fusion rates and cervical fusion rates are both increasing rapidly, while thoracic fusions continue to be less frequent. Lumbar fusions remain the most common, constituting 52% of all spine fusion procedures in 2011. Spinal refusions occur most often to the lumbar region, accounting for 65% of both refusion procedures and refusion patients. (Reference Table 2.14 PDF [5] CSV [6])
Using the Nationwide Inpatient Sample in 2011, a broad estimate can be made of fusion procedures as it relates to admissions. In 2011, 10.4% of patients with low back diagnosis were operated on with a fusion. For cervical neck pain diagnoses, the proportion is much higher (28.8%). Males and females are almost equally likely to have a fusion. The total number of males being fused for either neck or low back pain is 16.5% versus 14.4% among females. Patients in the 45- to 64-year age group were slightly more likely to have a fusion procedure than those younger or older. The length of stay was less if a fusion was performed than if no fusion was performed, but the mean charges were more than double when a fusion was performed. (Reference Table 2.15 PDF [7] CSV [8])
Spinal fusion is most frequently performed in patients with either a primary diagnosis of lumbar disc degeneration or cervical disc displacement, both accounting for 11.2% of fusion procedures. Spinal stenosis accounted for 10.6%. Much smaller numbers of patients had degenerative spondylolisthesis (7.5%), idiopathic spondylolisthesis (2.7%), or idiopathic scoliosis (2.4%). (Reference Table 2.16 PDF [9] CSV [10])
Diskectomies occurred in approximately 370,000 inpatients, with slightly more females than males undergoing the procedure. This number is likely misleading because many diskectomies now occur in an outpatient setting. Of those undergoing the procedures, 42% had a diagnosis of either lumbar or cervical disc displacement, with more than 12% having a diagnosis of disk degeneration. (Reference Table 2.18 PDF [11] CSV [12])
The largest number of patients with a diskectomy procedure (almost 50%) was in the 45- to 64-year age group. Patients spent on average 4.6 days in the hospital, although the median is between one and two days. Diskectomy procedures conducted in outpatient clinics are not included as there is no good source for this data at this time. The mean charges for diskectomy procedures were $35,000, for a total of $13 million. The majority of patients with a disc displacement diagnosis are not hospitalized. The most frequent encounters are physician office visits. (Reference Table 2.17 PDF [13] CSV [14])
Table 2.19 (PDF [15] CSV [16]) shows the diskectomy procedure trend in the United States from 1996 to 2011. It may seem surprising that the number is fairly stable given the population increase and the change in aging of the population. This is a reflection of the fact that more and more of these procedures are done in the outpatient setting and therefore not captured by the inpatient National Hospital Discharge Survey.
Links:
[1] https://www.boneandjointburden.org/docs/T2.12.pdf
[2] https://www.boneandjointburden.org/docs/T2.12.csv
[3] https://www.boneandjointburden.org/docs/T2.13.pdf
[4] https://www.boneandjointburden.org/docs/T2.13.csv
[5] https://www.boneandjointburden.org/docs/T2.14.pdf
[6] https://www.boneandjointburden.org/docs/T2.14.csv
[7] https://www.boneandjointburden.org/docs/T2.15.pdf
[8] https://www.boneandjointburden.org/docs/T2.15.csv
[9] https://www.boneandjointburden.org/docs/T2.16.pdf
[10] https://www.boneandjointburden.org/docs/T2.16.csv
[11] https://www.boneandjointburden.org/docs/T2.18.pdf
[12] https://www.boneandjointburden.org/docs/T2.18.csv
[13] https://www.boneandjointburden.org/docs/T2.17.pdf
[14] https://www.boneandjointburden.org/docs/T2.17.csv
[15] https://www.boneandjointburden.org/docs/T2.19.pdf
[16] https://www.boneandjointburden.org/docs/T2.19.csv